Graeme Lockley:
I am very intrested to know how does one, assuming it is possible,
use/implement inherited attributes in YACC.

Well, if you grant that yacc is already rather ugly, and uses global
variables all over the place, you might be happy just implementing a
[global] stack, and keeping track of these attributes there. [e.g. I
usually use a stack of symbol tables when implementing something using
yacc.]

Error recovery won't always be graceful, but then, with yacc it never
is. [Bison is much better here.]